Question

Match the y-coordinates with their corresponding pairs of x-coordinates on the unit circle. the x coordinates to choose from are: - 2 times the square root of 10/11 - 4 times the square root of 6/11 - 1/ the square root of 11 - 6 times the square root of 2/11

Answer 1

Of the four x-coordinates to choose only 1/√(11) belongs can belong to the unit circle.

The other three x-coordinates are greater than 1, then they are out of the unit circle.

The unit circle formula is x^2 +y^2 = 1

Then to find the y-coordinate given the x-coordinate you can solve for y from that formula:

y^2 = 1 - x^2

y = (+/-)√(1-x^2)

Substitute the value of x

y = (+/-)√{1 - [1/√(11)]^2} = (+/-) √{(1 - 1/11} =(+/-) √ {(11 -1)/11 =(+/-)√(10/11) ≈ +/- 0.95